1. Field of the Invention
This invention relates to manipulators with multiple degrees of freedom and t methods
2. Discussion of the Prior Art
Robot arms comprising links with multiple degrees of freedom have been developed to take the place of humans in the execution of manual work, while position control is carried out to realize operation with the same dexterity as a human.
The most basic hardware configuration of a manipulator is that in which each of the joints in the link mechanism comprises one actuator which drives the joint and a sensor which detects displacement of angle of the joint. Therefore, each joint of a manipulator normally has essentially independent positioning functions, so the number of degrees of freedom of the manipulator equals the number of actuators. While various techniques for controlling more degrees of freedom than the number of actuators have been proposed with the purpose of reducing the number of actuators, most of these are mechanism-dependent, such as methods in which differential mechanisms which follow objects are provided or methods in which mechanisms for transmission of power are provided.
Yet the conventional mechanism-dependent methods described above result in a more complex manipulator structure, with a concomitant high price, increasing the weight of the manipulator and requiring large amounts of driving energy.